 .mk_butt {
  border: 0;
  width: 51px;
  height: 31px;
  outline: none;
  font: normal 14px/31px "黑体";
  background: url(../img/btn_bg.png) no-repeat 0 0;
}
.act {
  color: #fff;
  background: url(../img/btn2.png) no-repeat 0 0;
}
